- Preparation method of calcium [beta]-hydroxy-[beta]-methylbutyrate
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The invention discloses a preparation method of calcium [beta]-hydroxy-[beta]-methylbutyrate, which comprises the following steps: S1) condensation reaction: adding ethyl chloroacetate and acetone into a solvent, and dropwisely adding an alkali solution to obtain a 3, 3-dimethyl oxide-2-carboxylic acid ethyl ester solution; S2) hydrolysis reaction: adding an aqueous solution of alkali into a solution of 3, 3-dimethyl oxide-2-carboxylic acid ethyl ester, and performing acidifying to obtain 3, 3-dimethyl oxide-2-carboxylic acid; S3) hydrogenation reaction: adding 3, 3-dimethyl oxide-2-carboxylicacid into the Pt/C alcohol system, and performing hydrogenation to obtain [beta]-hydroxy-[beta]-methylbutyrate acid; and S4) salifying reaction: adding water, calcium salt and a catalyst into the organic solution of [beta]-hydroxy-[beta]-methylbutyrate acid to react, and performing filtering, pulping and drying to prepare the finished product calcium [beta]-hydroxy-[beta]-methylbutyrate. The preparation method disclosed by the invention is simple in process, easy to operate, environment-friendly, free of pollution, safe in calcium reagent, free of residue, low in cost, safe to operate, easy for industrial large-scale production, high in conversion rate and good in product quality.
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Paragraph 0025; 0027-0052
(2020/07/24)
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- HERBICIDAL BENZOXAZINONES
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The present invention provides benzoxazinones of formula I wherein R1 is hydrogen or halogen; R2 is hydrogen, C1-C6-alkyl, C1-C6-haloalkyl, C3-C6-cycloalkyl, C3/
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Page/Page column 85
(2012/04/17)
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- Synthetic studies towards pectenotoxin-2: Synthesis of the nonanomeric 10-epi-ABCDE ring segment by kinetic spiroketalization
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The synthesis of the nonanomeric 10-epi-ABCDE ring system of pectenotoxin-2 has been achieved by using a kinetic spiroketalization reaction. The synthesis of the spiroketalization precursor was achieved through a cross-metathesis/ hydrogenation sequence.
- Aho, Jatta E.,Piisola, Antti,Syam Krishnan,Pihko, Petri M.
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supporting information; experimental part
p. 1682 - 1694
(2011/05/04)
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- Epoxidation of α,β-unsaturated esters by dimejhyldioxirane
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Kinetic data for the epoxidation of a series of α,β-unsaturated esters, 2-10, by dimethyldioxirane in dried acetone are reported. These epoxidations are less sensitive to steric effects and occur with lower k 2 values than those for simple alkenes. Relative reactivity could be modeled based on a spiro transition state mechanism. The density function calculations were in good agreement with the krel values except for those compounds with cis-β-substituents.
- Baumstark,Vasquez,Aly,Sansone
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scheme or table
p. 183 - 186
(2011/06/24)
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- Alternative protocol for oxidation in water: An effective epoxidation system promoted by the combination of Oxone and an amphiphilic ketone
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Epoxidation of cyclooctene and other alkenes with Oxone was promoted effectively in an aqueous micellar solution of an amphiphilic ketone, which was easily derived from hepta(ethylene glycol) monodecyl ether.
- Masuyama, Araki,Yamaguchi, Takashi,Abe, Manabu,Nojima, Masatomo
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p. 213 - 216
(2007/10/03)
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- Methode generale d'obtention des α-ceto esters β-fluores
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A general method of synthesis of 3-alkyl (or aryl) 3-fluoro 2-oxo esters is described.The opening of glycidic esters with HF-pyridine (70percent w/w) followed by oxidation with Jones reagent, give the corresponding derivatives of fluoropyruvic esters in good yields.
- Ourari, Ali,Condom, Roger,Guedj, Roger
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p. 2707 - 2710
(2007/10/02)
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